// Copyright 2014 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "src/arguments-inl.h"
#include "src/counters.h"
#include "src/heap/factory.h"
#include "src/heap/heap-inl.h"
#include "src/objects-inl.h"
#include "src/objects/js-generator-inl.h"
#include "src/runtime/runtime-utils.h"

namespace v8 {
namespace internal {

    RUNTIME_FUNCTION(Runtime_AsyncFunctionAwaitCaught)
    {
        // Runtime call is implemented in InterpreterIntrinsics and lowered in
        // JSIntrinsicLowering
        UNREACHABLE();
    }

    RUNTIME_FUNCTION(Runtime_AsyncFunctionAwaitUncaught)
    {
        // Runtime call is implemented in InterpreterIntrinsics and lowered in
        // JSIntrinsicLowering
        UNREACHABLE();
    }

    RUNTIME_FUNCTION(Runtime_AsyncFunctionEnter)
    {
        // Runtime call is implemented in InterpreterIntrinsics and lowered in
        // JSIntrinsicLowering
        UNREACHABLE();
    }

    RUNTIME_FUNCTION(Runtime_AsyncFunctionReject)
    {
        // Runtime call is implemented in InterpreterIntrinsics and lowered in
        // JSIntrinsicLowering
        UNREACHABLE();
    }

    RUNTIME_FUNCTION(Runtime_AsyncFunctionResolve)
    {
        // Runtime call is implemented in InterpreterIntrinsics and lowered in
        // JSIntrinsicLowering
        UNREACHABLE();
    }

    RUNTIME_FUNCTION(Runtime_CreateJSGeneratorObject)
    {
        HandleScope scope(isolate);
        DCHECK_EQ(2, args.length());
        CONVERT_ARG_HANDLE_CHECKED(JSFunction, function, 0);
        CONVERT_ARG_HANDLE_CHECKED(Object, receiver, 1);
        CHECK_IMPLIES(IsAsyncFunction(function->shared()->kind()),
            IsAsyncGeneratorFunction(function->shared()->kind()));
        CHECK(IsResumableFunction(function->shared()->kind()));

        // Underlying function needs to have bytecode available.
        DCHECK(function->shared()->HasBytecodeArray());
        int size = function->shared()->internal_formal_parameter_count() + function->shared()->GetBytecodeArray()->register_count();
        Handle<FixedArray> parameters_and_registers = isolate->factory()->NewFixedArray(size);

        Handle<JSGeneratorObject> generator = isolate->factory()->NewJSGeneratorObject(function);
        generator->set_function(*function);
        generator->set_context(isolate->context());
        generator->set_receiver(*receiver);
        generator->set_parameters_and_registers(*parameters_and_registers);
        generator->set_continuation(JSGeneratorObject::kGeneratorExecuting);
        if (generator->IsJSAsyncGeneratorObject()) {
            Handle<JSAsyncGeneratorObject>::cast(generator)->set_is_awaiting(0);
        }
        return *generator;
    }

    RUNTIME_FUNCTION(Runtime_GeneratorClose)
    {
        // Runtime call is implemented in InterpreterIntrinsics and lowered in
        // JSIntrinsicLowering
        UNREACHABLE();
    }

    RUNTIME_FUNCTION(Runtime_GeneratorGetFunction)
    {
        HandleScope scope(isolate);
        DCHECK_EQ(1, args.length());
        CONVERT_ARG_HANDLE_CHECKED(JSGeneratorObject, generator, 0);

        return generator->function();
    }

    RUNTIME_FUNCTION(Runtime_AsyncGeneratorAwaitCaught)
    {
        // Runtime call is implemented in InterpreterIntrinsics and lowered in
        // JSIntrinsicLowering
        UNREACHABLE();
    }

    RUNTIME_FUNCTION(Runtime_AsyncGeneratorAwaitUncaught)
    {
        // Runtime call is implemented in InterpreterIntrinsics and lowered in
        // JSIntrinsicLowering
        UNREACHABLE();
    }

    RUNTIME_FUNCTION(Runtime_AsyncGeneratorResolve)
    {
        // Runtime call is implemented in InterpreterIntrinsics and lowered in
        // JSIntrinsicLowering
        UNREACHABLE();
    }

    RUNTIME_FUNCTION(Runtime_AsyncGeneratorReject)
    {
        // Runtime call is implemented in InterpreterIntrinsics and lowered in
        // JSIntrinsicLowering
        UNREACHABLE();
    }

    RUNTIME_FUNCTION(Runtime_AsyncGeneratorYield)
    {
        // Runtime call is implemented in InterpreterIntrinsics and lowered in
        // JSIntrinsicLowering
        UNREACHABLE();
    }

    RUNTIME_FUNCTION(Runtime_GeneratorGetResumeMode)
    {
        // Runtime call is implemented in InterpreterIntrinsics and lowered in
        // JSIntrinsicLowering
        UNREACHABLE();
    }

    // Return true if {generator}'s PC has a catch handler. This allows
    // catch prediction to happen from the AsyncGeneratorResumeNext stub.
    RUNTIME_FUNCTION(Runtime_AsyncGeneratorHasCatchHandlerForPC)
    {
        DisallowHeapAllocation no_allocation_scope;
        DCHECK_EQ(1, args.length());
        CONVERT_ARG_CHECKED(JSAsyncGeneratorObject, generator, 0);

        int state = generator->continuation();
        DCHECK_NE(state, JSAsyncGeneratorObject::kGeneratorExecuting);

        // If state is 0 ("suspendedStart"), there is guaranteed to be no catch
        // handler. Otherwise, if state is below 0, the generator is closed and will
        // not reach a catch handler.
        if (state < 1)
            return ReadOnlyRoots(isolate).false_value();

        SharedFunctionInfo shared = generator->function()->shared();
        DCHECK(shared->HasBytecodeArray());
        HandlerTable handler_table(shared->GetBytecodeArray());

        int pc = Smi::cast(generator->input_or_debug_pos())->value();
        HandlerTable::CatchPrediction catch_prediction = HandlerTable::ASYNC_AWAIT;
        handler_table.LookupRange(pc, nullptr, &catch_prediction);
        return isolate->heap()->ToBoolean(catch_prediction == HandlerTable::CAUGHT);
    }

} // namespace internal
} // namespace v8
